The U.S. Food and Drug Administration has taken action against 17 companies illegally selling more than 58 products, many as dietary supplements, that claim to treat Alzheimer’s disease and other serious diseases and health conditions.

The 12 warning letters and 5 online advisory letters said the products are “unapproved new drugs and/or misbranded drugs” that have been sold in violation of the Federal Food, Drug and Cosmetic Act, as they claim to prevent, treat or cure Alzheimer’s and other diseases. The products include those sold as tablets, capsules and oils.

“These products, which are often sold on websites and social media platforms, have not been reviewed by the FDA and are not proven safe and effective to treat the diseases and health conditions they claim to treat,” the FDA said in a statement. “These products may be ineffective, unsafe and could prevent a person from seeking an appropriate diagnosis and treatment.”

The companies warned have been asked to respond to the FDA within days, stating how the violations will be corrected. Failure to correct the violations promptly may result in legal action, the FDA said.

The actions are part of the FDA’s efforts to address the growth of the dietary supplement industry, which has grown to a $40 billion industry, with anywhere between 50,000 and 80,000 or more products, from a $4 billion industry with 4,000 products, in the 25 years since Congress passed the Dietary Supplement Health and Education Act (DSHEA).

Three out of four Americans take a daily dietary supplement, including one in three children and teens and four of five older Americans.

“Science and evidence are the cornerstone of the FDA’s review process and are imperative to demonstrating medical benefit, especially when a product is marketed to treat serious and complex diseases like Alzheimer’s,” FDA Commissioner Scott Gottlieb said. “Simply put, health fraud scams prey on vulnerable populations, waste money and often delay proper medical care – and we will continue to take action to protect patients and caregivers from misleading, unproven products.”

“We welcome the need to look ahead but FDA cannot ignore today’s challenges in the meantime: Their inaction on one of the hottest products, CBDs, is a case in point,” said the Natural Products Association in a statement.

The ETFMG Alternative Harvest exchange-traded fund
MJ, +0.70%
has rallied 2.7% over the past three months and the Horizons Marijuana Life Sciences Index ETF
HMMJ, +0.00%
has slipped 0.8%, while the S&P 500 index
SPX, +0.23%
has declined 2.6%.

Intraday Data provided by SIX Financial Information and subject to terms of use. Historical and current end-of-day data provided by SIX Financial Information. All quotes are in local exchange time. Real-time last sale data for U.S. stock quotes reflect trades reported through Nasdaq only. Intraday data delayed at least 15 minutes or per exchange requirements.